Boat support frame loading and unloading apparatus

ABSTRACT

In one aspect the invention provides a boat support frame loading and unloading apparatus configured to draw a boat on to and off a boat support frame. This boat support frame has a loading end and a terminal end opposite to the loading end. The apparatus provided includes at least one roller assembly mounted to the support frame adjacent to the loading end of the support frame, said at least one roller assembly incorporating at least one roller element. The apparatus also includes at least one drive mechanism configured to rotate one or more roller elements to draw a boat onto and off the support frame through the loading end of the support frame. The roller assembly also includes a hull contact surface formed by a flexible belt which has a circumference greater than the circumference of the said at least one roller element incorporated into the roller assembly.

This application is a United States national phase filing ofPCT/NZ2015/050053, filed May 13, 2015, which claims priority to NZ624986, filed May 14, 2014, both of which are hereby incorporated byreference herein in their entireties.

TECHNICAL FIELD

This invention relates to a boat support frame loading and unloadingapparatus. In various embodiments the invention may be used to load andunload boats from mobile towed support frames, static support frameassemblies, or static support frames implemented in association withanother form of vehicle.

BACKGROUND ART

Various applications require boats to be moved to and from a supportframe and a body water.

For example road going trailers are commonly used to transport boatsoverland and to store boats away from a body of water. Boat trailersallow a wide range of different sizes of water vessels to be deployed toand retrieved from bodies of water.

Relatively simple boat trailers rely on the trailer being backed down aboat ramp and partially submerging the trailer. This then allows a boatto be pushed off the trailer with the assistance of a number of passiveroller elements. When the boat is to be retrieved it must be accuratelyaligned with the trailer to allow a winch system to be used to pull theboat back over the trailer rollers.

Winch based retrieval systems are difficult for some users to employeffectively, while also requiring the boat and the trailer to beprecisely aligned with the winch rope secured to a strong point at thebow of the boat. Furthermore, the loading of boat trailers with wincheswill normally result in the boat user getting wet.

Winch based systems—whether they be manually cranked or driven by anelectric motor—are also relatively slow. It is not uncommon for winchingoperations to take five or more minutes to load a boat depending on boatramp angle. Gearing systems are also employed with winches used toretrieve relatively heavy boats, allowing the winch to a load the boatbut at the cost of significantly slower loading speeds.

Boat trailers must also be at least partially submerged for relativelylong periods to allow for winch based loading operations. This approachwill expose the trailer frame and its associated components to water(and frequently saltwater) which can damage the trailer components. Saltwater exposure in particular is very common for boat trailers and has ahighly corrosive effect on metal components.

Attempts have been made to address these issues through providing boatloading systems which incorporate powered loading rollers.

For example, US patent specification U.S. Pat. No. 4,363,590 disclosesthe provision of an electric motor mounted to the rear of a boat trailerframe. This motor is connected to a rear mounted powered roller systemvia a system of drive shafts and gears. The electric motor rotates theroller system to launch a boat from the trailer or to retrieve a boatwhich has had its bow pushed up into contact with the powered rollers.

Although improving on winch based loading operations the approachdescribed by U.S. Pat. No. 4,363,590 normally ends up submerging theelectric motor used in water, and salt water in many cases. Thisapproach can drastically shorten the useful lifespan of the electricmotor and will promote accelerated metallic corrosion of the drivesystem components.

Furthermore the active or working components of this loading system aredifficult to access for repair and maintenance operations. Theseproblems are aggravated by this loading systems use of a relativelycomplicated power transmission system which again must be maintainedregularly to ensure effective and reliable operation of the device.

An alternative powered roller based loading system is disclosed in theapplicant's own PCT patent specification, published as WO2013/191570.This document discloses the provision of a number of powered rollersmounted to the rear of a boat trailer, with rotation of the rollersbeing driven by a hydraulic, pneumatic or electric motors mounted to theoutside end of each powered roller.

Although positioning the motor used in an accessible location, thepowered roller loading system disclosed in this document causes problemswhen a variety of boats with different hull shapes and designs are to beloaded. Depending on the hull chine shape involved there is thepotential for the upper sections of the hull to impact against thepowered roller drive motor as the boat is drawn on to the trailer.

In addition to needing to accommodate various hull chine shapes a boatframe loading and unloading systems must also accommodate hull designfeatures such as planing or lifting lines and lifting strakes. Thesefeatures are provided in various configurations and dimensions to assistin lifting the hull in the water when underway.

Lifting strakes are usually accommodated by providing a soft deformablecovering material over the trailer rollers to prevent damage to the hullas is drawn on to or off the trailer. However this approach is notparticularly effective as the lifting strakes create a local point loadon the roller which compresses the cover material and can still allowhull damage to occur.

The applicant's own PCT patent specification publication WO2013191570also attempts to address this problem in a limited fashion with a set ofstatic roller positions capable of flexing to a limited degree. Althoughmore effective than just deploying a deformable cover roller material,this approach is still only effective for a limited number of hulldesign configurations.

A similar set of operational constraints and performance issues are alsoexperienced with other forms of boat loading and unloading systems.

For example dry dock facilities are used to retrieve boats from bodiesof water, generally for the purposes of repairs and maintenance. Drydocks can rely on water locks and large water pumping systems oralternatively submergible support frames which run up and down boatloading ramps. Invariably the components used in the implementation of adry dock require a significant financial investment.

Smaller scale dock facilities are also desirable in boat housefacilities which in practice function as garages for boats formed asstandalone structures or as part of shorefront houses. It is common fora lifting cradle to be used in these applications, where a support frameis submerged and then lifted up underneath a boat driven into the house.These submergible frames are relatively large complicated pieces ofequipment which must be precisely aligned with a boat before it can belifted from the water by a high power drive system.

Drive on pontoon dock based facilities are also used to remove small andmedium size boats from bodies of water. These systems consist offloating platforms tethered to static sites and provide an upper decksurface which a vessel can force its way on to as its bow depresses theleading edge of the dock. Although providing a portable lightweightloading system for a static location, these systems provide littlecontrol to the user during loading operations. The user must force theirboat up onto the floating deck of the dock using the power of their ownboat only—with too fast an approach resulting in overshooting the deckand significant damage to the boat.

In some instances there is also the need to launch and retrieve a boatfrom a larger water vessel which acts as a mother ship. For examplelarge luxury water craft—commonly known as ‘super yachts’—can be used tolaunch and retrieve a variety of smaller water vessels such as smallerpower boats, jet skis or tender vessels.

Again in these applications some form of boat support frame needs to beloaded and unloaded, with the problems discussed above being aggravatedby the support frame also moving around on the surface of the waterwhile a boat is to be loaded. In such applications it is advantageous toload a boat as quickly as possible while avoiding the use of winchsystems which could be potentially dangerous to their users.

It would therefore be of advantage to have improvements over the priorart which addressed the above issues or at least provided the publicwith an alternative choice. In particular, it would be of advantage tohave a fast usable boat loading and unloading system capable of workingwith a wide range of sizes and weights of boats. A boat loading andunloading system with a robust design which protected its activecomponents from damage and water exposure would also be of advantage, aswould a system with flexible operational characteristics capable ofworking a variety of hull designs without damage.

DISCLOSURE OF INVENTION

According to one aspect of the present invention there is provided aboat support frame loading and unloading apparatus configured to draw aboat on to and off a boat support frame, the boat support frame having aloading end and a terminal end opposite to the loading end, theapparatus including

at least one roller assembly mounted to the support frame adjacent tothe loading end of the support frame, said at least one roller assemblyincorporating at least one roller element, and

at least one drive mechanism configured to rotate one or more rollerelements to draw a boat onto and off the support frame through theloading end of the support frame,

wherein a roller assembly includes a hull contact surface formed by aflexible belt which has a circumference greater than the circumferenceof the said at least one roller element incorporated into the rollerassembly.

According to another aspect of the present invention there is provided aboat support frame loading and unloading apparatus configured to draw aboat on to and off a boat support frame, the boat support frame having aloading end and a terminal end opposite to the loading end, theapparatus including

at least one roller assembly mounted to the support frame adjacent tothe loading end of the support frame, and

at least one drive mechanism configured to rotate one or more rollerelements of said at least one roller assembly to draw a boat on to andoff the support frame through the loading end of the support frame,

wherein said at least one roller assembly defines an exterior hullcontact surface and has an axis of rotation which rotates the hullcontact surface in contact with a boat hull, the drive mechanism used torotate a roller element being positioned co-axially with the rollerelement axis of rotation and surrounded by the hull contact surface ofthe roller assembly.

According to another aspect of the present invention there is provided aboat support frame loading and unloading apparatus configured to draw aboat on to and off a boat support frame, the boat support frame having aloading end and a terminal end opposite to the loading end, theapparatus including

at least one roller assembly mounted to the support frame adjacent tothe loading end of the support frame, and

at least one drive mechanism configured to rotate one or more rollerassemblies to draw a boat onto and off the support frame through theloading end of the support frame,

wherein a roller assembly includes one or more roller elementsdistributed along the length of the roller assembly, said roller elementdefining at least a portion of the roller assembly hull contact surface,the positioning of each roller element being adjustable within theloading and unloading apparatus.

According to a further aspect of the present invention there is provideda boat support frame loading and unloading apparatus substantially asdescribed above wherein a roller assembly includes two or more rollerelements distributed along the length of the roller assembly, saidroller elements defining the roller assembly hull contact surface, thepositioning of the roller elements relative to each other beingadjustable within the roller assembly by the insertion or removal of atleast one spacing element located between adjacent roller elements.

According to yet another aspect of the present invention there isprovided a boat support frame loading and unloading apparatussubstantially as described above which includes a mounting bracketassociated with each roller assembly, said mounting bracket beingengaged with opposite ends of the roller assembly and including atelescoping support shaft extending the length of the roller assembly,the length of the support shaft being adjustable to accommodatemodifications in the length of the roller assembly.

According to another aspect of the present invention there is provided aboat support frame loading and unloading apparatus substantially asdescribed above which includes a carrier arm arranged to connect theloading and unloading apparatus to a boat support frame, one end of thecarrier arm being connected to a mounting bracket associated with aroller assembly, the connection position of the carrier arm to themounting bracket being adjustable to adjust the position of the rollerassembly within the loading and unloading apparatus.

According to a yet further aspect of the present invention there isprovided a method of operating a loading and unloading apparatussubstantially as described above to load a boat to a support framewithin a maximum acceptable time period, characterised by the steps of:

i. determining the weight and length of the boat to be loaded, and

ii. calculating the force required to load the boat within the maximumacceptable time period

iii. calculating the torque required to load the boat using thecalculated force and a measurement of the diameter of the rollerassembly or assemblies

iv. calculating the operational speed required of the roller assemblydrive mechanism or mechanisms to develop the calculated torque

v. operating the drive mechanism or mechanisms at the calculatedoperational speed to load the boat within the maximum acceptable timeperiod.

Preferably the above method also includes the preliminary step ofdetermining the hull material type. For example, this method may involvethe reception of preliminary information regarding whether a hull isformed from a metal alloy, GRP or other forms of compounds.

According to a yet another aspect of the present invention there isprovided a method of specifying the construction of a loading andunloading apparatus substantially as described above to load a boat to asupport frame within a maximum acceptable time period, characterised bythe steps of:

i. determining the weight and length of the boat to be loaded, and

ii. calculating the force required to load the boat within the maximumacceptable time period

iii. calculating the torque required to load the boat using thecalculated force and a measurement of the diameter of the rollerassembly or assemblies to be constructed

iv. calculating the operational speed required of the roller assemblydrive mechanism or mechanisms to develop the calculated torque

v. specifying the configuration of the drive mechanism required tooperate at the speed calculated to load the boat within the maximumacceptable time period.

Preferably the above method also includes the preliminary step ofdetermining the hull material type. For example, this method may involvethe reception of preliminary information regarding whether a hull isformed from a metal alloy, GRP or other forms of compounds.

The present invention is arranged to provide a loading and unloadingapparatus used in conjunction with a boat support frame. The boatsupport frames employed with the invention define a loading end and aterminal end, where a boat is loaded in to and on to the frame throughthe loading end with the bow of the boat eventually ending up adjacentto the terminal end of the frame.

The invention may be used with a range of different types of the supportframes, such as for example, those implemented by road going trailers,or alternatively with support frames used in dry dock applications, boathouses, floating pontoon docks or with larger water vessels.

Reference in general throughout this specification will be made to theinvention being installed on or forming part of a road going boattrailer. However those skilled in the art will appreciate that theinvention may be used with any number of alternative forms of boatsupport frame and references to its use with boat trailers in isolationshould not be seen as limiting.

Referenced in general throughout this specification will also be made tothe invention providing a loading apparatus. Again those skilled in theart will appreciate that the invention can obviously be employed tounload a boat from a support frame in addition to loading boats to thesame frame.

Reference in general throughout this specification is also made to theinvention being used to load and unload boats. Those skilled in the artwill appreciate that the term boat encompasses a wide range of forms ofwater vessels from large single hull vessels, multihull vessels orsmaller craft such as jet skis.

The invention is implemented by providing one or more roller assembliesin association with one or more drive mechanisms. A roller assemblydefines or includes at least one roller element in addition to a hullcontact surface which when rotated by a drive mechanism acting on aroller element will engage with the hull of a boat to load or unload theboat from a trailer.

In various embodiments the hull contact surface can have a substantiallycylindrical form with a central axis of rotation, and may be fixed inplace on or be formed by the exterior surface of one or more rollerelements integrated in a roller assembly. Activation of a drivemechanism associated with the roller element will cause the hull contactsurface to bear against a boat hull, with rotation of the roller elementurging the boat on or off the associated boat support frame.

In other embodiments a hull contact surface may be formed from a loop orbelt of flexible material with a greater circumference than that of theroller element. In these cases a contact surface may form a conveyerbelt loop which is tensioned or shaped by a further rotor elementlocated distal to a driving roller element. Activation of a drivemechanism associated with a roller element will rotate the hull contactconveyer belt surface around the roller element with one side of thebelt surface engaging with the hull of a boat to draw the boat onto oroff the boat support frame.

The invention's roller assembly or assemblies are mounted to the boattrailer adjacent to the loading end of the trailer. This configurationof the invention allows a boat to be loaded simply by its operatorpositioning the bow of the boat into contact with the roller assembly.The drive mechanism can then be activated to allow the roller assemblieshull contact surface to rotate against and pull the boat on to thetrailer. The reverse of this operation can also be run to launch a boatfrom the trailer.

Those skilled in the art will appreciate that various arrangements andconfigurations of roller assemblies and drive mechanisms may be employedin different embodiments of the invention.

For example in one alternative embodiment a trailer frame may beprovided with a single roller assembly, while in other embodimentsmultiple sets of roller assemblies may be deployed to the rear loadingend of the trailer.

Furthermore in some embodiments each roller assembly provided may berotated by a single dedicated drive mechanism, while in otherembodiments multiple drive mechanisms may be provided for a rollerassembly.

Referenced in general throughout this specification will however be madeto the invention being implemented in a preferred embodiment to providemultiple roller assemblies with a boat trailer where each rollerassembly is rotated or powered by a single drive mechanism. Againhowever those skilled in the art will appreciate that alternativeconfigurations of the invention are also possible.

In a preferred embodiment a drive mechanism may be provided by ahydraulic motor. Hydraulic motors are relatively simple drive systems,needing only to be supplied with pressurised hydraulic fluid to functioneffectively. These types of drive mechanisms can also function todeliver high torques to the hull contact surface, allowing heavy boatsto be loaded easily and quickly.

Reference in general throughout this specification will also be made tothe invention employing drive mechanisms formed from hydraulic motors.Again however those skilled in the art will appreciate that alternativeforms of drive systems may also be employed with the invention inalternative embodiments.

As referenced above, in various embodiments a hull contact surface maybe formed from a loop or belt of flexible material with a greatercircumference than that of the roller element. In such embodiments thehull contact surface belt will be free to move over an associated rollerelement used to impart a rotary motion to the hull contact surface belt.

In such embodiments the roller assembly providing the hull contactsurface belt can also include a tension rotor which is located distalfrom a roller assembly used to impart rotary motion to the belt. Atension rotor can be formed by any appropriate component which is ablestretch or tension the belt and also rotate and guide the motion of thehull contact belt back towards a driving roller element.

For example in one such embodiments a tension rotor may be provided by asimple passive cylindrical roller which tensions and shapes the hullcontact surface belt and guides its motion back towards a driving rollerelement.

Furthermore, in alternative configurations a tension rotor may beprovided by a further roller element of the same roller assembly. Inthese instances the contact surface belt can be shaped and tensioned byat least two roller elements which are aligned along separate rotationalaxes and which can be rotated by one or more drive mechanisms.

In various embodiments where a hull contact surface belt is provided bya roller assembly one or more guide rollers may also be provided by thesame roller assembly. In such embodiments one or more guide rollers maybe positioned between a tension rotor and a driving roller element toguide the motion of the belt as it rotates over the roller element andtension rotor. As is the case with the tension rotor, a guide roller maybe formed by a passive cylindrical roller, or could potentially bedriven to add to the rotary motion imparted to the hull contact surfacebelt. Those skilled in the art will appreciate that one or more guiderollers may be used to control the shape of the belt while alsocontrolling the route it travels between tension rotor and rollerelement.

In various embodiment the invention is arranged to position the drivemechanism used to rotate this roller assembly coaxially with the axis ofrotation of the cylindrical hull contact surface while also surroundingthe drive mechanism with the hull contact surface.

As referenced above, in various embodiments each roller assemblyprovided by the invention can define or incorporate a substantiallycylindrical exterior hull contact surface where the roller has an axisof rotation which rotates the hull contact surface into contact with aboat hull.

In such embodiments the drive mechanism used to rotate a roller elementmay be located within the interior of one or more roller elements,enclosing the drive mechanism within the substantially cylindrical formof the hull contact surface. The drive mechanism is therefore positionedat a location which prevents it from being impacted by the hull of aboat being loaded, but also retains this component in a readilyaccessible location which is unlikely to be submerged for long periodsof time.

However, in other alternative embodiments where a hull contact surfacebelt is provided by a roller assembly the entire drive mechanism usedmay not necessarily be enclosed within a roller element. In theseembodiments the roller assembly can incorporate a tension rotor whichdraws out extends and tensions the hull contact surface belt to form ordefine a substantially flat or plane like surface from one side of thebelt to be placed in contact with the hull of a boat. The combination ofthe tension rotor and roller element will therefore form a flat driveplane in the hull contact surface belt.

In various preferred implementations of such embodiments the drivemechanism and its associated drive shaft may be positioned so that therotational axis of the driveshaft is not aligned with the flat driveplane of the hull contact surface belt. For example in some embodimentsa guide roller may be provided with a roller assembly to verticallyoffset the drive plane of the hull contact surface belt from the drivemechanism and its associated driveshaft. In such embodiments a guideroller may be used to lift the hull contact surface belt upwards beforeit forms such a drive plane, leaving the drive mechanism position belowwhere the drive assembly contacts the boat hull. This arrangement willtherefore vertically offset the drive mechanism from the drive plane andposition the drive mechanism at a location which prevents it from beingimpacted by the hull of a boat being loaded.

In some embodiments the loading apparatus includes a mounting bracketassociated with each roller assembly. This mounting bracket may be usedin embodiments where the roller elements are aligned along the same axisof rotation.

In such embodiments this mounting bracket is engaged with the oppositeterminal ends of the roller assembly and includes a support shaft whichextends the length of the roller assembly. This support shaft runs alongthe length of the roller assembly in parallel with and adjacent to theroller assembly, with the ends of the mounting bracket connected tosupport shaft, enclosing the terminal ends of the roller assembly.

In preferred forms of this embodiment the mounting bracket support shaftmay be implemented with a telescoping form to allow the length of thesupport shaft be adjusted to accommodate modifications in the length ofthe roller assembly. The length of the mounting bracket may therefore beadjusted as required depending on the length and configuration of theroller assembly to be employed in a particular embodiment.

In a preferred embodiment a mounting bracket may be engaged with asupport frame through the provision of an intervening carrier arm. Thiscarrier arm may extend from the mounting bracket to position a rollerassembly adjacent to the loading end of the frame.

Preferably one end of the carrier arm is connected to a mounting bracketassociated with a roller assembly, where the connection position of thecarrier arm to the mounting bracket can adjustable to adjust theposition of the roller assembly within the loading and unloadingapparatus.

In a further preferred embodiment a carrier arm may be connected to thesupport shaft of the mounting bracket by way of a sliding connectionsleeve. This sleeve may be fixed to the end of the carrier arm whilebeing arranged to slide up and down the length of the support shaft. Avariety of different forms of locking systems—such as for example abearing screw or similar element—may then be engaged to hold the end ofthe mounting bracket at a particular point on the mounting bracketsupport shaft.

In yet other embodiments where a roller assembly provides a hull contactsurface belt the various components of a roller assembly may be mountedon and positioned by a roller assembly chassis. This chassis can act asa mounting frame which also assisting in the mounting of the rollerassembly to the associated boat support frame.

In preferred forms of such embodiments the exterior sidewalls and/orexposed upper surfaces of the roller assembly chassis may be coated in adeformable resilient guard material. This guard material can provide aprotective layer over components of the chassis which may damage thehull of a boat being loaded or unloaded as it moves over the chassis.For example in some embodiments a guard material formed from a softplastic or rubber may be used to coping upper edges and exterior sidesof the roller assembly chassis.

In such embodiments the chassis of a roller assembly may be mounted to aboat support frame through the use of an intervening mounting post.

This mounting post can be connected to the roller assembly chassis by anintervening longitudinal pivot connector engaged with a lateral pivotconnector, the longitudinal pivot connector and lateral pivot connectoreach being arranged to rotate about a different axis of rotation. Insuch embodiments the axis of rotation of the longitudinal pivotconnector can be substantially perpendicular to the axis of rotation ofthe lateral pivot connector.

This arrangement of the mounting post and associated pivot connectorscan therefore allow the roller assembly some freedom of movement to sitat a complementary angle to the hull of a boat being loaded or unloaded.Each of the lateral and longitudinal pivot connectors can allow theroller assembly and associated hull contact surface belt to tiltforwards, backwards, or side to side to engage with a boat hull.

In some embodiments where a roller assembly provides a hull contactsurface belt the mounting post may also include an orientation biasingelement. This orientation element can be used to place the mounted driveassembly and in a preferred initial loading orientation when the boatsupport frame is unloaded. Preferably in such instances the hull contactsurface belt may be orientated so that the end of the belt adjacent tothe loading end of the frame is lower than the opposite end of the belt.This initial loading orientation will therefore present a steeply angleddrive plane of the hull contact surface belt to the incoming bow of aboat. As boat bows tend to angle upwards steeply, this orientationoptimises the surface area of the hull contact surface belt immediatelyin contact with the hull and capable of engaging with and pulling thehull on to the support frame.

In some implementations of these embodiments an orientation biasingelement may be formed from a spring or other similar component. Aspraying can provide the necessary angle to the hull contact surfacebelt when installed between a roller assembly chassis and associatedmounting post. Once the roller assembly is loaded this spring elementwill be compressed and the roller assembly will be free to adjust itsorientation to suit that of the incoming or outgoing profile of the boathull.

In yet other implementations and orientation biasing element may beformed by a similar deformable resilient structure such as for example adense foam rubber or plastic block or shim. This shim of resilientmaterial can be positioned between the roller assembly chassis andmounting post to initially urge the roller assembly into a desiredinitial loading orientation. The weight of a boat being loaded or loadedwill then compress the resilient shim and allow the roller assembly toadjust its orientation to suit that of the hull on the frame.

In yet another implementation this biasing element may also be formed bya drive mechanism associated with the roller assembly. In suchembodiments the drive mechanism may be is positioned orientated towardsthe loading end of the frame and at one end of the roller assembly, withthe weight of the drive mechanism being used to bias the roller assemblyinto the desired initial loading orientation.

In some embodiments the hull contact surface of a roller assembly isformed by or has a fixed connection to one or more roller elements.These roller elements are in turn engaged with the rotating componentsof a drive mechanism thereby allowing the drive mechanism to rotate thehull contact surface. For example in one preferred form of thisembodiment a drive mechanism formed by a hydraulic motor may extend arotating driveshaft along the interior of a roller element, with theroller element being connected to this driveshaft to allow for rotationof the whole contact surface provided by the roller element.

Preferably a roller element may have a substantially cylindrical formwith a hollow central region running the length of the roller element.This hollow central region may be used in preferred embodiments toposition and accommodate at least a portion of a drive mechanism.

In some embodiments where roller elements are aligned along the sameaxis of rotation a roller element may include a deformable or resilientcover material which is used to contact the hull of a boat being loaded.

For example in one embodiment a dense cover layer of elastomericmaterial may be provided as part of a roller element.

In yet another of these embodiments the outer surface of a rollerelement may be formed by portions of an inflatable bladder used tocontain a volume of liquid, gel, or pressurized gas. This form ofbladder can therefore deform around and conform to the shape of a hullpassing over the roller element, providing a high degree of surface areacontact to the hull while minimising the chance of the hull being damageby contact with the roller assembly.

In yet further embodiments the where a hull contact surface belt isprovided by a roller assembly a roller element may be provided with asubstantially cylindrical form with the exterior of the form defining aplurality of gripping projections. These gripping projections may assistthe roller element in gripping the inside surface of the hull contactsurface belt and imparting a rotary motion.

In embodiments where a hull contact surface belt is provided by a rollerassembly the flexible loop of material used may also have variousfeatures defined on its surfaces. For example, in some embodiments theinner surface of the belt which contacts a roller element may define aplurality of gripping projections adapted to engage with the rollerelement. In other—or potentially the same—embodiment the otter surfaceof the belt which contacts a boat hull may define a plurality ofgripping projections adapted to engage with the hull of a boat.

A hull contact surface belt used in such embodiments may also be formedby a variety of materials. For example in various embodiments this beltmay be formed from any one or combination of rubber, PVC, thermoplasticelastane, thermoplastic urethane, polyurethane and/or neoprene.

Those skilled in the art will appreciate that in various embodiments aroller assembly may be formed from one, two or potentially more distinctroller elements depending on the application in which the invention isemployed. Furthermore in some embodiments or the roller elements of aroller assembly may be rotated by a single drive mechanism, whereas inother embodiments different roller elements of the same assembly may berotated by separate drive mechanisms.

In yet other embodiments roller elements making up a roller assembly maynot be aligned along a common axis of rotation. For example in instanceswhere the hull contact surface of a roller assembly is formed by a loopor belt of flexible material with a circumference greater than that of aroller element, the roller elements may be displaced from each other toseparate the axis of rotation of each roller element. In suchembodiments the roller elements can act to tension the hull contactconveyer belt and to drive the motion of the conveyer belt.

In some embodiments where roller elements are aligned along the sameaxis of rotation the location of a roller element may be adjusted tovarious positions along the length of the roller assembly, or relativeto the entire loading and unloading apparatus. By allowing the positionof the inventions roller elements to be adjusted this allows the loadingapparatus to be configured to load a wide variety of hull shapes withvarious design features.

For example, in one embodiment where a single roller assembly includes aplurality of axially aligned roller elements, the positioning orrelative spacing of these roller elements may be adjusted by theinsertion or removal of one or more spacing elements. The spacingelements may be deployed along the length of the axially aligned rollerassembly and be located between the adjacent roller elements or at theends of the roller assembly. Spacing elements can have a form or profilewith a substantially smaller radius than that of the roller elements.The spacing element therefore defines a cavity in the substantiallycylindrical profile of the roller assembly which is capable of receivingfeatures such as planning strakes projecting from the hull of a boat.

In yet other embodiments the position of a single roller element makingup a roller assembly may be adjusted to accommodate variations in hulldesign and form. In such embodiments the position at which a carrier armis engaged with the roller assembly mounting bracket can be adjusted toin turn adjust the relative position of the roller element in relationto the boat support frame and hence what portions of the hull of a boatbeing loaded will be contacted.

Those skilled in the art will also appreciate that roller assembliescomposed of multiple axially aligned roller elements can also bepositioned using the connection point of a carrier arm to the mountingbracket involved. Again the position of these roller elements may beadjusted in this way to adjust the relative position of the rollerelements in relation to the boat support frame and therefore whichportions of the hull of a boat will be contacted.

In some embodiments a lifting structure may be provided in combinationwith a roller assembly and any associated drive mechanism engaged withthis roller assembly. A lifting structure may be deployed between theboat support frame and roller assembly and can be used to adjust therelative vertical position or location of a roller assembly whencompared to the boat support frame.

A lifting assembly can therefore be used to adjust the angle which acontact surface makes with the hull of a boat as it is loaded orunloaded. Furthermore, a lifting structure may also be used to ensurethat the weight of a boat bears against the hull contact surface withenough force to frictionally engage the boat with the hull contactsurface. Those skilled in the art will appreciate that this liftingassembly may be used in a range of embodiments of the invention, be itto lift and lower a roller assembly with axially aligned rollerelements, or a roller assembly which provides a hull contact surfacebelt.

In some embodiments a boat loading frame may include further sets ofpassive rollers deployed towards the middle and terminal end of theframe. These additional mid and fore passive rollers allow a boat to berolled into its final loaded position on the frame, but will alsolighten the load applied by the boat to a roller assembly as the boatmoves towards the terminal end of the frame. As less weight is borne bya roller assembly its ability to grip and push against the hull of aboat is diminished. A lifting structure can therefore be used to liftthe boat hull up and off these additional passive rollers for a longerportion of the loading operation time.

In a preferred embodiment a lifting structure may include or be formedfrom a compression element. A compression element provided in this rolecan be arranged to both lift an associated roller assembly when notloaded by the weight of a boat, and also lower the same roller assemblyin a controlled manner as a boat is loaded towards the terminal end ofthe frame. This compression element may in some embodiments have aresilient character, ensuring that the associated roller assembly can belifted above the main body of the boat loading frame prior to any boatloading operations.

For example in one embodiment a lifting structure may incorporate acompression element formed by a spring. The resilient character of thisspring will therefore raise an associated roller assembly upwards whennot loaded by the weight of the boat, while lowering the roller assemblyin a controlled manner as more weight is applied to it by a boat duringa loading operation.

However in a preferred embodiment a compression element may be formed bya hydraulic or pneumatic ram assembly. In such embodiments a ram chambermay be charged with pressurised gas or liquid to raise an associatedroller assembly prior to the loading operation. During loading thehydraulic or pneumatic fluid involved can be allowed to exit from theram chamber at a controlled flow rate, thereby allowing the rollerassembly to be lowered at a controlled rate during the boat loadingoperation.

BRIEF DESCRIPTION OF THE DRAWINGS

Example embodiments of the invention are now discussed with reference tothe drawings in which:

FIGS. 1a and 1b show perspective views of the invention implemented intwo different embodiments to load and unload boats from a road goingtrailer,

FIGS. 2 and 3 show exploded and assembled views of a roller assembly andassociated mounting bracket as provided in two further embodiments,

FIG. 4 shows a selection of front views of elements the inventionimplemented in the embodiment of FIG. 3, each view showing thereconfiguration of the invention to adjust the length and positioning ofthe roller elements of a roller assembly,

FIGS. 5a and 5b show end and plan views of the roller assembly of FIG. 1b,

FIGS. 6a, 6b show a set of perspective views of the roller assembly,connection bracket and carrier arm of the embodiment shown with respectto FIG. 1a , and

FIGS. 7a, 7b show a set of perspective views of the roller assembly,connection bracket and carrier arm of the embodiment shown with respectto FIG. 1b

FIG. 8 shows a perspective view of a pair of roller assemblies andassociated drive mechanisms deployed on a boat loading road trailerframe in accordance with a further embodiment of the invention, and

FIGS. 9a, 9b and 9c show top, side and end view of one of the rollerassemblies and drive mechanisms of the embodiment of FIG. 8, and

FIGS. 10a through 10d show front and rear perspective views andunderside views of the roller assembly and drive mechanism of theembodiment of FIGS. 9a through 9c , and

FIG. 11 shows a side cross-section view of the roller assembly and drivemechanism illustrated with respect to FIGS. 9 and 10.

FIGS. 12a through 12c show a sequence of side cross section views of theroller assembly and drive mechanism of FIGS. 9 through 11 illustratingthe action of the lifting structure provided in this embodiment.

FIGS. 13a through 13c show a corresponding sequence of end views of theroller assemblies, drive mechanisms and boat loading road trailer ofFIGS. 8 through 12 illustrating the action of the lifting structureprovided in this embodiment.

BEST MODES FOR CARRYING OUT THE INVENTION

FIGS. 1a and 1b shows a perspective view of the invention used in twodifferent embodiments to implement a loading and unloading apparatus 1for a boat support frame formed from a road going trailer 2.

In this embodiment the invention is formed by a number of rollerassemblies 3 positioned to the rear or loading end of the trailer. Theroller assembles 3 are deployed with a symmetrical arrangement centeredaround the midline of the trailer frame 4.

In the embodiment shown with respect to FIG. 1a the roller assemblies 3include a single roller element 5, while in the embodiment of FIG. 1b apair of adjacent aligned roller elements 5 are provided.

Each roller assembly is enclosed by the ends of a mounting bracket 6with each mounting bracket 6 connected to a carrier arm 7 to locate theroller assembly 3 in place on the trailer frame 4. The same carrier arm7 is also used to deploy a passive roller 8 and provides the inventionwith a pivoting ‘wobble roller’ arrangement with a pivoting connection 9to the trailer frame 4. Those skilled in the art will appreciate howeverthat in other embodiments the carrier arm may be directly fixed to aframe and therefore would be unable to move relative to this frame.

Boat loading and unloading operations are completed with the activationof a drive mechanism (not shown) associated with each roller assembly.These drive mechanisms rotate the exterior hull contact surfaces of theroller assemblies to push the stern of a boat off the trailer or to drawthe bow of a boat on to the trailer. The hull contact surfaces of eachroller assembly continue to rotate until the boat is either launchedfrom the trailer or the bow of the boat comes to rest at the terminalend of the trailer.

FIGS. 2 and 3 show exploded and assembled views of a roller assembly andassociated mounting bracket as provided in two further embodiments.

The roller assembly is formed in these embodiments from a pair of rollerelements 5 aligned end to end to define the length of the rollerassembly 3. The exterior surface of the roller elements forms the hullcontact surface 10 of the roller assembly.

Each roller element has a substantially cylindrical form and defines ahollow central region 11. The centre of one of the roller elements isused to accommodate a drive mechanism hydraulic motor 12. Locating thehydraulic motor inside one of the roller elements positions itco-axially with the roller assembly axis of rotation, with the motorbeing surrounded by the hull contact surface. The hydraulic motorextends a rotating driveshaft 13 which is connected to both the rollerelements to impart rotational movement to these components when themotor is activated.

In the configuration of the invention shown with respect to FIG. 2 theroller elements 5 are located immediately adjacent to one another.Conversely FIG. 3 shows the provision of a spacing element 14 betweenthe two roller elements. The spacing element separates the rollerelements, creating a void which is able to receive a planing strakeprojecting from the hull of a boat. As can also see be seen from FIG. 3the spacing element also acts as a section of the hydraulic motor'sdriveshaft, rotating when the motor is activated to transfer the motorsrotational energy to the second roller element.

FIGS. 2 and 3 also illustrate the form and arrangement of a telescopingsupport shaft 15 provided by the mounting bracket 6. As can be seen ineach of the exploded views the support shaft is provided by a two orthree part arrangement of concentrically nested box section shafts.These nested shafts are slid into and out of one another until thelength of the mounting bracket matches that of the roller assembly.

FIG. 4 shows a selection of front views of the invention implemented inthe embodiment of FIG. 3. Each of these views show the reconfigurationof the invention to adjust the length and positioning of the rollerelements of the roller assembly.

As can be seen from FIG. 4 the length of each roller assembly can beadjusted through the insertion of an intervening spacing element 14between the two roller elements. The size of the spacing element usedwill dictate the spacing between the roller elements.

FIGS. 5a and 5b show end and plan views of the roller assembly of FIG. 1b.

FIG. 5a illustrates elements of a locking system used in conjunctionwith the telescoping support shaft of the mounting bracket. The supportshaft 15 is implemented with an arrangement of three complimentarynested box section shafts, with a pair of slots 16 formed near the endsof the outer middle shaft. These slots 16 allow a locking screw, bolt orsimilar component to engage with the surface of the inner section of theshaft and lock it to the middle section at a selected position.

FIG. 5b illustrates the provision of a sliding connection sleeve 17 usedto adjust the connection point of the carrier arm 7 to the supportshaft, and hence the position of the roller assembly relative to thetrailer frame. As can be seen from FIG. 5b this sleeve encircles thesupport shaft and is free to connect to carrier arm to it at anyposition along its length.

The operation of this sliding connection sleeve is also shown in moredetail with respect to FIGS. 6a-6b and FIGS. 7a-7b . FIGS. 6a, 6b show aset of perspective views of the roller assembly, connection bracket andcarrier arm of the embodiment shown with respect to FIG. 1a . ConverselyFIGS. 7a, 7b show a set of perspective views of the roller assembly,connection bracket and carrier arm of the embodiment shown with respectto FIG. 1 b.

As can be seen from these figures the position at which the slidingconnection sleeve 17 is locked to the end of the carrier arm 7 willdictate the relative position of the roller assembly 3 to the traileronce connected through the pivoting connection point 9 of the carrierarm.

FIG. 8 shows a perspective view of a boat support frame loading andunloading apparatus 101 as provided by an alternative embodiment of theinvention. The apparatus 101 provides a pair of roller assemblies 103and associated drive mechanisms 112 deployed on a boat loading roadtrailer frame 104 in accordance with a this embodiment of the invention.

The two roller assemblies 103 are positioned to the rear or loading endof the trailer frame 104. The roller assembles are again deployed with asymmetrical arrangement centered on the midline of the trailer frame.

As can be seen in more detail with respect to FIGS. 9a-c and 10a-d ,each of the roller assemblies 103 are formed with a single rollerelement 105. Each roller element has a substantially cylindrical formwith the centre of this form used to accommodate the drive shaft 113 ofa drive mechanism, which is provided in this embodiment by a hydraulicmotor 112. This arrangement positions the hydraulic motor co-axiallywith the roller element axis of rotation.

In this embodiment each roller assembly includes a hull contact surfaceso formed by a flexible belt 110 which has a circumference greater thanthe circumference of the roller element 105. Each hull contact surfacebelt is free to move over the roller element, with rotation of theroller element imparting a rotary motion to the hull contact surfacebelt. The direction of rotation imparted to the belt is shown by thelongitudinal arrow illustrated by FIG. 9 a.

The various components of each roller assembly are mounted on andpositioned by a roller assembly chassis 118. The chassis aids indefining the path traveled by the hull contact surface belt 110 as itrotates while also providing an attachment mechanism for the rollerassembly to the boat loading frame 104.

The exterior sidewalls of the roller assembly chassis are coated in adeformable resilient rubber guard material 119. This guard materialprovides a protective layer over components of the chassis which maydamage the hull of a boat being loaded or unloaded as it moves over thechassis.

As illustrated by FIG. 11, the hull contact surface belt 110 istensioned or shaped by a further tension rotor located at the oppositeend of the chassis to the roller assembly. The tension rotor is formedby a passive cylindrical roller 120 which tensions and shapes the hullcontact surface belt 110 and guides its motion back towards the drivingroller element 105.

The roller assembly also includes three guide rollers 121 positionedbetween the tension rotor and driving roller element. As is the casewith the tension rotor 120, each guide roller 121 is formed by a passivecylindrical roller which guides the path of the belt through the chassis118 as it rotates over the roller element 105 and tension rotor 120.

Boat loading and unloading operations are completed with the activationof the drive mechanism 112 associated with each roller assembly 103.These drive mechanisms rotate the hull contact surface belt 110 of theroller assemblies to push the stern of a boat off the trailer 104 or todraw the bow of a boat on to the trailer. The hull contact surface beltof each roller assembly continue to rotate until the boat is eitherlaunched from the trailer or the bow of the boat comes to rest at theterminal end of the trailer.

As can be seen from FIGS. 9 and 10 the roller element 105, guide rollers121 and tension rotor 120 define a substantially flat drive plane 122 onthe side of the belt 110 to be placed in contact with the hull of aboat. The guide roller closest to the roller element is used tovertically offset the drive plane of the hull contact surface belt fromthe drive mechanism 112 and its associated driveshaft 113. This guideroller lifts the hull contact surface belt upwards before it forms thedrive plane, leaving the drive mechanism positioned below where theroller assembly contacts the boat hull. This arrangement will thereforeposition the drive mechanism at a location which prevents it from beingimpacted by the hull of a boat being loaded.

The relative position or orientation of each roller assembly andassociated drive mechanism can also be modified in this embodimentthrough the mounting systems used to connect these components to theboat loading trailer frame.

The embodiment shown with respect to FIGS. 8 through 13 illustrates theuse of a mounting post 123 to connect each drive assembly 103 to thetrailer frame 104.

The mounting post 123 is connected to the roller assembly chassis by anintervening longitudinal pivot connector 124 engaged with a lateralpivot connector 125. Each pivot connector 124, 125 is arranged to rotateabout a different axis of rotation to adjust the range of motionafforded to a roller assembly and the contact angle it makes withvarious areas of a boat hull. In the embodiment illustrated the axis ofrotation of the longitudinal pivot connector is perpendicular to theaxis of rotation of the lateral pivot connector.

This arrangement allows the roller assembly to sit at a complementaryangle to the hull of a boat being loaded or unloaded. Each of thelateral and longitudinal pivot connectors 124, 125 can allow the rollerassembly and associated hull contact surface belt to tilt forwards,backwards, or side to side to engage to engage the greatest surface areaof the belt with a boat hull. The freedom of orientation provided to thedrive assembly is shown by the longitudinal pivot arrow of FIG. 9b andthe transverse pivot arrow of FIG. 9 c.

In the embodiment shown with respect to FIGS. 8 to 12 a liftingstructure 126 is provided in combination with the support post. Thislifting structure incorporates a compressible element formed by ahydraulic ram 127 which is located within a rectangular pressure housing128 which also defines the body of the mounting post. The ram is free tomove up and down inside the pressure housing but is locked in a fixedorientation within the housing by a rectangular collar.

The lifting structure is therefore deployed between the boat supportframe and roller assembly and is used to adjust the relative verticalposition or location of the roller assembly when compared to the boatsupport frame. In use the pressure housing 128 is charged withpressurised hydraulic fluid to raise the ram 127 and associated rollerassembly 103 prior to a loading operation. This initial loading positionof the roller assembly is shown with respect to FIG. 12 a.

During loading hydraulic fluid is allowed to exit from the pressurehousing 128 at a controlled flow rate, with the mid-point of thisprocess shown with respect to FIG. 12b . This structure therefore allowsthe roller assembly to be lowered at a controlled rate during the boatloading operation, with the final position of the roller assembly beingshown with respect to FIG. 12 c.

FIGS. 13a through 13c illustrate the position of the roller assemblyshown in each of FIGS. 12a through 12b when mounted on the boat loadingframe of FIG. 8.

In particular, FIG. 13a shows each roller assembly 103 placed in aninitial lifted loading position prior to the loading of a boat to theframe. As can be seen from FIG. 13a the roller assembly 103 is lifted toapproximately the same height as a set of passive loading rollers 129mounted to the mid-point of the loading frame.

FIG. 13b shows the incremental lowering of each roller assembly whichoccurs as a boat is loaded onto the frame. As can be seem from thisfigure each roller assembly 103 is still close to the height of themid-point rollers 129 and would be starting to transfer the weight ofthe boat to these rollers.

FIG. 13c shows the final position of the roller assemblies 103 once aboat is loaded, with each assembly dropping below the frame's mid-pointrollers 129 once the boat is completely loaded.

It is to be understood that the present invention is not limited to theembodiments described herein and further and additional embodimentswithin the spirit and scope of the invention will be apparent to theskilled reader from the examples illustrated with reference to thedrawings. In particular, the invention may reside in any combination offeatures described herein, or may reside in alternative embodiments orcombinations of these features with known equivalents to given features.Modifications and variations of the example embodiments of the inventiondiscussed above will be apparent to those skilled in the art and may bemade without departure of the scope of the invention.

What we claim is:
 1. A boat support frame loading and unloadingapparatus configured to draw a boat on to and off a boat support frame,the apparatus comprising: a boat support frame having a loading end anda terminal end opposite to the loading end; and at least two rollerassemblies mounted opposite one another symmetrically about a midline ofthe boat support frame adjacent to the loading end of the boat supportframe, each roller assembly incorporating: at least one roller element,at least one drive mechanism configured to rotate one or more of the atleast one roller elements to draw a boat onto and off the boat supportframe through the loading end of the boat support frame, a hull contactsurface formed by a flexible belt formed in a loop with a circumferencegreater than a circumference of the at least one roller element, theflexible belt configured to move over the at least one roller element asthe at least one roller element is rotated by the at least one drivemechanism to rotate the flexible belt, and a tension rotor locateddistal from the at least one roller element rotated by the at least onedrive mechanism and at least one guide roller, the at least one tensionrotor and the at least one guide roller configured to tension or shapethe flexible belt to define a substantially flat drive plane on a sideof the loop to be placed in contact with a hull of the boat, wherein theat least one roller element rotated by the at least one drive mechanismis vertically offset from the tension rotor and the at least one guideroller such that the at least one drive mechanism and the at least oneroller element driven by the at least one drive mechanism are positionedbelow the substantially flat drive plane.
 2. The apparatus of claim 1,wherein the boat support frame loading and unloading apparatus forms aroad going boat trailer.
 3. The apparatus of claim 1, wherein the atleast one drive mechanism is formed by a hydraulic motor.
 4. Theapparatus of claim 1, wherein the tension rotor is formed by a passiveroller.
 5. The apparatus of claim 1, wherein the at least one guideroller is positioned between the tension rotor and the at least oneroller element to guide the motion of the loop when rotated over theroller element and tension rotor.
 6. The apparatus of claim 1, whereinthe at least one roller element has a substantially cylindrical formwith the exterior of the form defining a plurality of grippingprojections.
 7. The apparatus of claim 1, wherein each roller assemblycomprises a roller assembly chassis, the at least one roller elementrotated by the at least one drive mechanism, the tension rotor and theat least one guide roller mounted on and positioned by the rollerassembly chassis.
 8. The apparatus of claim 7 wherein the rollerassembly chassis is connected to the boat support frame by a mountingpost.
 9. The apparatus of claim 8, wherein the mounting post isconnected to the roller assembly chassis by an intervening longitudinalpivot connector engaged with a lateral pivot connector, the longitudinalpivot connector and lateral pivot connector each being arranged torotate about a different axis of rotation, the axis of rotation of thelongitudinal pivot connector being substantially perpendicular to theaxis of rotation of the lateral pivot connector.
 10. The apparatus ofclaim 1, wherein each roller assembly is connected to a boat supportframe using a lifting structure.
 11. The apparatus of claim 10, whereinthe lifting structure comprises a compression element.
 12. The apparatusof claim 11, wherein the compression element comprises a hydraulic ram.13. The apparatus of claim 11, wherein the compression element comprisesa pneumatic ram.
 14. The apparatus of claim 1, wherein the substantiallyflat drive plane is not aligned with the rotational axis of a driveshaft of the drive mechanism.